1. Field of the Invention
The present invention is related to the field of two channel tape recorders which can be converted to four channel operation.
2. Description of the Prior Art
Two channel tape recorders are designed so that a magnetic head is moved up and down to monitor pairs of track information which exist on a magnetic tape. Normally, eight tracks of information are provided on a tape. The first and fifth tracks are monitored first, the second and sixth tracks are monitored second, the third and seventh tracks are monitored third, and the fourth and eighth tracks are monitored last.
In four channel tape recorders the magnetic head is designed to simultaneously monitor four tracks of information on the magnetic tape. Normally, the first, third, fifth and seventh tracks are monitored first and the second, fourth, sixth and eighth tracks are then monitored.
A typical prior head indexing system which can be readily adapted for combined quad and stereo tape players used two coaxially mounted cam surfaces which were selectively coupled to the magnetic head depending upon whether a four or eight track tape cartridge was inserted. Such a system is described in U.S. Pat. No. 3,787,058. This system requires two sets of precision cam surfaces and clutch mechanisms to shift the coaxially mounted cam surfaces.